JP2018172640A - Acid-cleavable monomer and polymers including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide copolymers derived from an iodine-containing monomer.SOLUTION: A copolymer comprises a polymerized product of a monomer having formula (I). In formula (I), "G" represents a cyclic structure, and "I" represents iodine.SELECTED DRAWING: None

Description

  The present disclosure generally relates to a polymer composition comprising a photoacid generator. Specifically, the present disclosure provides copolymers derived from iodine-containing monomers.

  Extreme ultraviolet lithography (EUVL) is one of the state-of-the-art options for replacing optical lithography for volume semiconductor manufacturing with a feature size of <20 nm. The very short wavelength (13.4 nm) is a key factor in the high resolution required by multiple technology generations. Furthermore, the overall system concepts such as scanning exposure, projection optics, mask format, and resist technology are very similar to those used in current optical technology. Like the conventional lithography generation, EUVL consists of resist technology, exposure tool technology, and mask technology. An important issue is EUV power supply power and throughput. Any improvement in the EUV power supply directly affects current stringent resist sensitivity specifications. Indeed, the main problem in EUVL imaging is resist sensitivity, the lower the sensitivity, the greater the power supply power required or the longer the exposure time required to fully expose the resist. The lower the power level, the more noise affects the line edge roughness (LER) of the print line.

  Improving EUV sensitivity is a key factor. EUV light absorption cross section and secondary electron production yield have been shown to be important factors in EUV sensitivity. One way to increase EUV photoresist sensitivity is to increase its absorption cross section at 13.5 nm, which is an atomic property of the material that can be theoretically calculated using known atomic absorption. is there. Typical atoms that make up resist materials such as carbon, oxygen, hydrogen, and nitrogen have very weak absorption at 13.5 nm. Fluorine atoms have slightly higher absorption and are used in the search for high EUV absorption photoresists.

  Iodine has a significantly higher absorption cross section in EUV irradiation. Recent patent application JP2015-161823 discloses iodine-containing monomers and corresponding polymers useful for lithographic processing. However, none of these monomers could be easily cleaved by acid. Thus, there remains a need for new iodine-containing superabsorbent monomers to produce iodine-containing polymers that can be useful in lithographic processing.

  An embodiment is a monomer having the formula (I)

In formula (I):
R ^a is H, F, —CN, a C _1-10 alkyl group, or a C _1-10 fluoroalkyl group,
R ¹ and R ² are each independently an unsubstituted or substituted C _1-10 linear or branched alkyl group, an unsubstituted or substituted C _3-10 cycloalkyl group, an unsubstituted or substituted C _3-10 alkenylalkyl group. , An unsubstituted or substituted C _3-10 alkynylalkyl group, or an unsubstituted or substituted C _6-30 aryl group, wherein R ¹ and R ² optionally represent at least one linking group selected from O and S R ¹ and R ² together optionally form a ring;

_Represents a monocyclic or polycyclic unsubstituted or substituted C _6-30 arylene group, or a monocyclic or polycyclic unsubstituted or substituted C _3-30 heteroarylene group, “*” and “* ′” Indicate the point of attachment to an adjacent group or atom;
“I” represents iodine;
n provides a monomer that is 1, 2, 3, 4, 5, 6, 7, 8, and 9.

  Another embodiment provides a copolymer comprising the polymerization product of a monomer having formula (I) and at least one unsaturated monomer different from the monomer having formula (I).

  Yet another embodiment provides a copolymer comprising a polymerization product of a photoacid generator monomer comprising a polymerizable group and a monomer having formula (I).

  DETAILED DESCRIPTION Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the exemplary embodiments may have different forms and should not be construed as limited to the description set forth herein. Accordingly, the exemplary embodiments are merely described below with reference to the drawings to illustrate aspects herein. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. When an expression such as “at least one” precedes a list of elements, it modifies the entire list of elements and does not change the individual elements of the list.

  When an element is referred to as being “on” another element, it is understood that it can be in direct contact with the other element or there can be intervening elements therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

  Although terms such as first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components , Regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Accordingly, a first element, component, region, layer, or section described below is referred to as a second element, component, region, layer, or section without departing from the teachings of this embodiment. Can do.

  The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

  As used herein, the terms “comprises” and / or “comprising”, or “includes” and / or “including” are described features, regions Identifying the presence of an integer, step, operation, element and / or component, but the presence or presence of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof It will be further understood that this does not exclude additions.

  As used herein, “about” or “approximately” includes the stated value and takes into account the measurement in question and the error associated with the measurement of the particular quantity (ie the limitations of the measurement system) It means within an acceptable deviation range for a particular value as determined by one skilled in the art. For example, “about” can mean within one or more standard deviations, or within ± 30%, 20%, 10%, 5% of the indicated value.

  Unless defined otherwise, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms as defined in commonly used dictionaries should be construed as having a meaning consistent with the meaning in the context of the related art and this disclosure, and are clearly defined herein. It will be further understood that unless otherwise interpreted in an idealized or overly formal sense.

  As used herein, unless otherwise defined, the term “alkyl group” is a straight or branched chain saturated compound having the specified number of carbon atoms and having at least a monovalent valence. Refers to a group derived from an aliphatic hydrocarbon.

  As used herein, unless otherwise defined, the term “fluoroalkyl group” refers to an alkyl group in which one or more hydrogen atoms are replaced with fluorine atoms.

  As used herein, unless otherwise defined, the term “alkoxy group” refers to “alkyl-O—”, where the term “alkyl” has the same meaning as above.

  As used herein, unless otherwise defined, the term “fluoroalkoxy group” refers to an alkoxy group in which one or more hydrogen atoms have been replaced with fluorine atoms.

  As used herein, unless otherwise defined, the term “cycloalkyl group” refers to a monovalent group having one or more saturated rings in which all ring members are carbon.

  As used herein, unless otherwise defined, the term “alkenyl group” refers to a straight or branched monovalent hydrocarbon group having at least one carbon-carbon double bond.

  As used herein, unless otherwise defined, the term “alkenylalkyl group” refers to “alkenyl-alkyl-”, where the terms “alkenyl” and “alkyl” have the same meanings as described above.

  As used herein, unless otherwise defined, the term “alkynyl group” refers to a straight or branched monovalent hydrocarbon group having at least one carbon-carbon triple bond.

  As used herein, unless otherwise defined, the term “alkynylalkyl group” refers to “alkynyl-alkyl-”, where the terms “alkynyl” and “alkyl” have the same meanings as described above.

  As used herein, unless otherwise defined, the term “aryl”, used alone or in combination, includes aromatic or heteroaromatic compounds containing at least one ring and having a specified number of carbon atoms. Refers to a group hydrocarbon. The term “aryl” can be taken to include groups having an aromatic or heteroaromatic ring fused to at least one cycloalkyl or heterocycloalkyl ring. An “aryl” group may contain one or more heteroatoms independently selected from nitrogen (N), oxygen (O), P (phosphorus) and sulfur (S).

  As used herein, unless otherwise defined, the term “aryloxy group” refers to “aryl-O—”, wherein the term “aryl” has the same meaning as described above.

  As used herein, unless otherwise defined, the term “aralkyl group” refers to a substituted or unsubstituted aryl group covalently bonded to an alkyl group that is bonded to the compound.

  As used herein, unless otherwise defined, the term “alkylene group” refers to a straight or branched saturated aliphatic hydrocarbon group having at least two valences, optionally an alkylene group. May be substituted with one or more substituents where indicated.

  As used herein, unless otherwise defined, the term “cycloalkylene group” refers to a cyclic hydrocarbon group having at least two valences, optionally exceeding the valence of the cycloalkylene group. If not, it may be substituted with one or more substituents where indicated.

  As used herein, unless otherwise defined, the term “arylene group” refers to a functional group having a valence of at least 2 obtained by removing two hydrogens in an aromatic ring. Optionally, if the valence of the arylene group does not exceed, it may be substituted with one or more substituents where indicated.

  As used herein, unless otherwise defined, the term “aralkylene group” refers to a functional group having a valence of at least 2 obtained by removing two hydrogens from an alkyl-substituted aromatic compound; Optionally, provided that the valence of the aralkylene group does not exceed, where indicated, it may be substituted with one or more substituents.

  As used herein, unless otherwise defined, the term “heteroarylene group” refers to a functional group having a valence of at least 2 obtained by removing two hydrogens in a heteroaromatic ring. Optionally, if the valence of the heteroarylene group does not exceed, it may be substituted with one or more substituents where indicated.

  Embodiments of the present disclosure provide a monomer having formula (I).

In formula (I):
R ^a can be H, F, —CN, a C _1-10 alkyl group, or a C _1-10 fluoroalkyl group,
R ¹ and R ² are each independently an unsubstituted or substituted C _1-10 linear or branched alkyl group, an unsubstituted or substituted C _3-10 cycloalkyl group, an unsubstituted or substituted C _3-10 alkenylalkyl group. , An unsubstituted or substituted C _3-10 alkynylalkyl group, or an unsubstituted or substituted C _6-30 aryl group, wherein R ¹ and R ² are optionally at least one linking group selected from O and S R ¹ and R ² together can optionally form a ring,

_Represents a monocyclic or polycyclic unsubstituted or substituted C _6-30 arylene group, or a monocyclic or polycyclic unsubstituted or substituted C _3-30 heteroarylene group, “*” and “* ′” Can indicate the point of attachment to an adjacent group or atom;
“I” represents iodine;
n can be 1, 2, 3, 4, 5, 6, 7, 8, and 9.

In the above monomer, the C _6-30 arylene group may be a monocyclic C _6-30 arylene group, a condensed bicyclic C _6-30 arylene group, or a single bond C _6-30 arylene group. The C _6-30 arylene group can be a 1,2-phenylene group, a 1,3-phenylene group, and a 1,4-phenylene group. The fused bicyclic C _6-30 arylene group can be a disubstituted naphthalene group, a disubstituted anthracene group, or a disubstituted phenanthrene group. The single bond C _6-30 arylene group can be a disubstituted biphenylene group or a disubstituted terphenylene group. The C _3-30 heteroarylene group can be a monocyclic C _3-30 heteroarylene group, a fused bicyclic C _3-30 heteroarylene group, or a single bond C _3-30 heteroarylene group.

In one embodiment, each of R ¹ and R ² can be an unsubstituted or substituted C _1-10 linear or branched alkyl group. For example, both R ¹ and R ² can be an unsubstituted or substituted linear C _1-10 alkyl group, and ^one of R ¹ and R ² is an unsubstituted or substituted linear C _1-10 alkyl group Or the other of R ¹ and R ² can be an unsubstituted or substituted branched C _1-10 alkyl group, or both R ¹ and R ² can be an unsubstituted or substituted branched C _1-10 alkyl group possible. In an embodiment, ^one of R ¹ and R ² can be an unsubstituted C _1-10 linear or branched alkyl group, and the other of R ¹ and R ² is C ₁ -substituted with at least one fluorine atom. _{It can be 10} straight chain or branched alkyl groups.

Each of R ¹ and R ² can include a linking group selected from O and S. The linking group may be present inside R ¹ and R ² or may be present at the site of binding with the adjacent group. When a linking group is present inside, examples of groups R ¹ and R ² are CH ₃ OCH ₂ —, CH ₃ OCH ₂ CH ₂ —, CH ₃ CH ₂ OCH ₂ —. When linking groups are present at their binding sites, examples of groups R ¹ and R ² are CH ₃ O—, CH ₃ CH ₂ O—, and CH ₃ CH ₂ CH ₂ O—.

In one embodiment, the groups R ¹ and R ² may together form an optional ring. For example, when R ¹ is methyl and R ² is n-propyl, R ¹ and R ² may form a cyclopentane ring. In another example, when R ¹ is ethyl and R ² is n-propyl, R ¹ and R ² may form a cyclohexane ring.

  In the formula (I), the variable n represents the number of iodine atoms bonded to the divalent group.

  The number n of iodine atoms can vary depending on the nature of the group and can be 1, 2, 3, 4, 5, 6, 7, 8, or 9. For example, n can be 1, 2, or 3.

  Specific examples of monomers having the formula (I) can be represented by the following chemical formula.

  Another embodiment provides a copolymer comprising the polymerization product of a monomer having formula (I) and at least one unsaturated monomer different from the monomer having formula (I).

In formula (I), R ^a , R ¹ , R ² ,

  “I” and n are the same as described above.

  The unsaturated monomer different from the monomer having formula (I) can be a base-soluble monomer, a lactone-containing monomer, or a combination thereof.

  For example, the unsaturated monomer may be a base soluble monomer of formula (II).

In formula (II), Q ₁ can be an ester-containing group or a non-ester-containing group selected from C _1-20 alkyl, C _3-20 cycloalkyl, C _6-20 aryl and C _7-20 aralkyl. In one embodiment, if it contains an ester, the ester can form bonds coupling between the coupling point for Q ₁ and to a double bond. Thus, when Q ₁ is an ester group, formula (II) may be a (meth) acrylate monomer. In another embodiment, when no ester is included, Q ₁ can be aromatic so that formula (II) can be, for example, a styrenic monomer or a vinyl naphthoic acid monomer. Q ₁ may be fluorinated or may not be fluorinated. In the formula (II), a may be an integer of 1 to 3, for example, a may be 1 or 2.

In Formula (II), W represents —C (═O) —OH, —C (CF ₃ ) ₂ OH, —NH—SO ₂ —Y ¹ (wherein Y ¹ represents F or C _{1- 4} perfluoroalkyl), aromatic-OH, or base-reactive groups including adducts of any of the above with vinyl ethers. In embodiments, when Q is non-aromatic (eg, when Formula (II) includes a (meth) acrylate structure having an ester linked alkyl or cycloalkyl group Q), W is —C (CF ₃ ) ₂ OH. It can be. In another embodiment, when Q is aromatic (eg, Q is either an ester bond or a non-ester bond and is an aromatic group such as phenyl or naphthyl), W is OH or —C (CF ₃ ) Can be ₂ OH. Any of the base-reactive groups has an acid-decomposable acetal leaving group (eg, the general structure —O—CH (R ′) — OR ″, where R ′ is methyl, ethyl, or other It is contemplated that it may be further protected by an alkyl group of Such groups include, for example, ethyl vinyl ether, propyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, 2-vinyloxyethyl ester of 1-adamantanecarboxylic acid, 2-naphthoyl ethyl vinyl ether, or other such vinyl ethers. Such an adduct of vinyl ether.

W may be a base reactive group comprising a fluorinated ester in the form of —C (═O) —OCF ₂ R or —OC (═O) CF ₂ R, where R is C _1-10 An alkyl group or a C _1-10 fluoroalkyl group;

  Exemplary base soluble monomers having the formula (II) are:

Or a combination comprising at least one of the above, wherein R ^a is H, F, C _1-6 alkyl, or C _1-6 fluoroalkyl.

  The unsaturated monomer can be a lactone-containing monomer of formula (III).

In formula (III), L can be a monocyclic, polycyclic, or fused polycyclic C _4-20 lactone-containing group. Such lactone groups can be included to improve the adhesion of the polymer to the substrate and the dissolution of the polymer in the basic developer. In one embodiment, L may be a monocyclic C _4-6 lactone attached to the (meth) acrylate moiety via a monocyclic ring carbon, or L is a C ₆₋ based on a norbornane-type structure. _It may be a _10- fused polycyclic lactone.

  In one embodiment, the lactone-containing monomer can have the formula (IIIa)

Where
R ^a is H, F, C _1-6 alkyl, or C _1-6 fluoroalkyl, R is C _1-10 alkyl, cycloalkyl, or heterocycloalkyl,
w is an integer of 0-6.

  In formula (IIIa), R may be a fraction, or may be bonded to a lactone ring and / or one or more R groups, and the methacrylate moiety is directly or indirectly through the lactone ring. It will be understood that they may be combined.

  Exemplary lactone-containing monomers of formulas (III) and (IIIa) are:

Or a combination comprising at least one of the above, wherein R ^a is H, F, C _1-6 alkyl, or C _1-6 fluoroalkyl.

  In one embodiment, the copolymer can comprise a polymerization product having the following structure:

Where
k, l, m, and q represent the mole fraction of the corresponding repeating unit;
“I” is iodine, and the variable n is the same as above.

Another embodiment further provides a photoresist composition comprising the copolymer and a non-polymerizable photoacid generator monomer having the formula G ⁺ A ⁻ , wherein A ⁻ is a non-polymerizable organic anion; G ⁺ has the formula (IV).

In formula (IV):
X can be S or I;
Each R ^c may be halogenated or non-halogenated and is independently a C _1-30 alkyl group, polycyclic or monocyclic C _3-30 cycloalkyl group, polycyclic or A monocyclic C _4-30 aryl group,
When X is S, one of the R ^c groups is optionally bonded to one adjacent R ^c group by a single bond, z is 2 or 3,
When X is I, z is 2, or when X is S, z is 3.

For example, the cation G ⁺ can have the formula (V), (VI), or (VII)

Where
X is I or S;
R ^h , R ⁱ , R ^j , and R ^k are unsubstituted or substituted and are each independently hydroxy, nitrile, halogen, C _1-30 alkyl, C _1-30 fluoroalkyl, C _3-30 cyclo Alkyl, C _1-30 fluorocycloalkyl, C _1-30 alkoxy, C _3-30 alkoxycarbonylalkyl, C _3-30 alkoxycarbonylalkoxy, C _3-30 cycloalkoxy, C _5-30 cycloalkoxycarbonylalkyl, C _{5 -30} cycloalkoxycarbonylalkoxy, _C1-30 fluoroalkoxy, _C3-30 fluoroalkoxycarbonylalkyl, _C3-30 fluoroalkoxycarbonylalkoxy, _C3-30 fluorocycloalkoxy, _C5-30 fluorocycloalkoxycarbonylalkyl , C _5-30 fluorocycloalkoxycarbonylalkoxy, C _6-30 aryl, C _6-30 fluoroaryl, C _6-30 aryloxy, or C _6-30 fluoroaryloxy, each of which is unsubstituted Or substituted
Ar ¹ and Ar ² are independently a C _10-30 condensed or single-bonded polycyclic aryl group,
R ¹ is a lone pair when X is I, or a C _6-20 aryl group when X is S;
p is an integer of 2 or 3, and when X is I, p is 2, when X is S, p is 3.
q and r are each independently an integer of 0 to 5;
s and t are each independently an integer of 0 to 4.

In formula (V), (VI), or (VII), at least one of R ^h , R ⁱ , R ^j , and R ^k can be an acid-cleavable group. In embodiments, acid-cleavable group, (i) a tertiary _{C 1-30} alkoxy (e.g., tert- butoxy group), a tertiary _{C 3-30} cycloalkoxy group, a tertiary _{C 1-30 Full} Oroalkoxy group, (ii) tertiary C _3-30 alkoxycarbonylalkyl group, tertiary C _5-30 cycloalkoxycarbonylalkyl group, tertiary C _3-30 fluoroalkoxycarbonylalkyl group, (iii) third A tertiary C _3-30 alkoxycarbonylalkoxy group, a tertiary C _5-30 cycloalkoxycarbonylalkoxy group, a tertiary C _3-30 fluoroalkoxycarbonylalkoxy group, or (iv) a moiety —O—C (R ¹¹ R ¹² ) -O- ^{(wherein, R} 11 ^{R 12} are each independently _{C 2-30} acetate containing hydrogen or a _{C 1-30} alkyl group) It may be Lumpur group.

  Photoresist compositions comprising the copolymers and non-polymerizable photoacid generator monomers disclosed herein can be used to provide a layer comprising a photoresist. The coated substrate may be formed from a photoresist composition. Such a coated substrate comprises: (a) a substrate having one or more layers patterned on its surface; and (b) a layer of a photoresist composition over the one or more layers to be patterned. ,including.

  The substrate may be of any size and shape and is useful for photolithography, such as silicon, silicon dioxide, silicon on insulator (SOI), strained silicon, gallium arsenide, silicon nitride, silicon oxynitride, Coated substrates, including substrates coated with ultra-thin gate oxides such as titanium nitride, tantalum nitride, hafnium oxide, coated with metal or titanium, tantalum, copper, aluminum, tungsten, alloys thereof, and combinations thereof A metal coated substrate including the substrate is preferred. Preferably, the surface of the substrate herein includes a critical dimension layer to be patterned, including, for example, one or more gate level layers or other critical dimension layers on a substrate for semiconductor manufacturing. Such a substrate is preferably formed as a circular wafer having dimensions such as 20 cm, diameters of 30 cm or more, or other dimensions useful for wafer assembly manufacturing, silicon, SOI, strained silicon and other Such a substrate material may be included.

  Also, the method for forming an electronic device includes (a) applying (casting) the layer of the photoresist composition to the surface of the substrate, and (b) pattern exposing the photoresist composition layer with activating radiation, (C) developing the exposed photoresist composition layer to provide a resist relief image.

  Application can be done by any suitable method including spin coating, spray coating, dip coating, doctor blade, and the like. Applying a layer of photoresist is preferably accomplished by spin coating the photoresist in a solvent using a coating track that is dispensed onto the wafer on which the photoresist is spinning. During dispensing, the wafer can be rotated at a speed of up to 4,000 rpm, preferably about 200-3,000 rpm, more preferably 1,000-2,500 rpm. The coated wafer is rotated to remove the solvent and baked on a hot plate to remove residual solvent and free volume from the film, and densify uniformly.

  The casting solvent can be any suitable solvent known to those skilled in the art. For example, casting solvents include aliphatic hydrocarbons (eg, hexane, heptane, etc.), aromatic hydrocarbons (eg, toluene, xylene, etc.), halogenated hydrocarbons (eg, dichloromethane, 1,2-dichloroethane, 1-chloro Hexane), alcohol (methanol, ethanol, 1-propanol, iso-propanol, tert-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol, etc.), water, ether (eg, diethyl ether, Tetrahydrofuran, 1,4-dioxane, anisole, etc.), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, cyclohexanone, etc.), esters (eg, ethyl acetate, n-butyl acetate, propylene glycol monomethyl) Ether acetate (“PGMEA”), ethyl lactate, ethyl acetoacetate, etc., lactone (eg, γ-butyrolactone, ε-caprolactone, etc.), nitrile (eg, acetonitrile, propionitrile, etc.), aprotic dipolar solvent (eg, , Dimethyl sulfoxide, dimethylformamide, etc.), or combinations thereof. The choice of casting solvent depends on the particular photoresist composition and can be readily made by one skilled in the art based on knowledge and experience.

  Next, pattern exposure is achieved by irradiating the film through a pattern mask using an exposure apparatus such as a stepper to achieve pattern exposure. The method preferably uses an advanced exposure tool that generates activating radiation at wavelengths capable of high resolution, including extreme ultraviolet ("EUV") or electron beam irradiation. It is understood that exposure with activating radiation decomposes the PAG in the exposed areas to produce acid and decomposition byproducts, which then cause chemical changes in the polymer and nanoparticles. As such (deblocking acid sensitive groups to produce base soluble groups, or alternatively catalyzing the crosslinking reaction in the exposed areas). The resolution of such an exposure tool can be less than 30 nm.

  Then developing the exposed photoresist layer selectively removes the exposed layer of the exposed layer of the film (where the photoresist is positive tone) or removes the unexposed part of the film. This is accomplished by treatment with a suitable developer that can be removed (where the photoresist is crosslinkable in the exposed areas, ie negative tone). Preferably, the photoresist is a negative tone based on a polymer having pendant and / or free acid groups or byproducts (derived from bound PAG or free PAG after irradiation) that inhibit dissolution of the nanoparticles, Is preferably a solvent system. A pattern is formed by development. The solvent developer can be any suitable developer known in the art. For example, solvent developers include aliphatic hydrocarbons (eg, hexane, heptane, etc.), aromatic hydrocarbons (eg, toluene, xylene, etc.), halogenated hydrocarbons (eg, dichloromethane, 1,2-dichloroethane, 1- Chlorohexane, etc.), alcohol (methanol, ethanol, 1-propanol, iso-propanol, tert-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol, etc.), water, ether (eg, diethyl ether) , Tetrahydrofuran, 1,4-dioxane, anisole, etc.), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, cyclohexanone, etc.), esters (eg, ethyl acetate, n-butyl acetate, propylene glycol monomethyl ether) Acetate (“PGMEA”), ethyl lactate, ethyl acetoacetate, etc.), lactone (eg, γ-butyrolactone, ε-caprolactone, etc.), nitrile (eg, acetonitrile, propionitrile, etc.), aprotic dipolar solvent (eg, Dimethyl sulfoxide, dimethylformamide, etc.), or combinations thereof. In one embodiment, the solvent developer may be a miscible mixture of solvents, such as a mixture of alcohol (iso-propanol) and ketone (acetone). The choice of developer solvent depends on the particular photoresist composition and can be readily made by one skilled in the art based on knowledge and experience.

  Photoresist, when used in one or more such patterning processes, produces electronic and optoelectronic devices such as memory devices, processor chips (CPUs), graphics chips, and other such devices. Can be used for.

  Yet another embodiment provides a copolymer comprising a polymerization product of a photoacid generator monomer comprising a polymerizable group and a monomer having formula (I).

In formula (I), R ^a , R ¹ , R ² ,

  “I” and n are the same as described above.

  The photoacid generator monomer containing a polymerizable group can be represented by the formula (VIII).

In formula (VIII), each R ^a can independently be H, F, a C _1-10 alkyl group, or a C _1-10 fluoroalkyl group. “Fluoro” or “fluorinated” as used throughout this specification means that one or more fluorine groups are attached to the relevant group. For example, unless otherwise specified, by this definition, “fluoroalkyl” includes monofluoroalkyl, difluoroalkyl, and the like, and perfluoroalkyl in which substantially all of the carbon atoms of the alkyl group are substituted with fluorine atoms, and the like In addition, “fluoroaryl” means monofluoroaryl, perfluoroaryl and the like. “Substantially all” in this context means that 90% or more, preferably 95% or more, even more preferably 98% or more of all atoms bonded to carbon are fluorine atoms.

In formula (VIII), Q ₂ is a single bond or an ester-containing or non-ester-containing fluorination selected from C _1-20 alkyl, C _3-20 cycloalkyl, C _6-20 aryl, and C _7-20 aralkyl. Or it is a non-fluorinated group. For example, if it contains an ester, the ester forms a bond linkage between the point of attachment to Q ₂ with the double bond. Thus, when _{Q 2} is an ester group of the formula (VIII) may be (meth) acrylate monomer. If not include esters, Q ₂ is obtained is aromatic, the result of the formula (VIII) may be, for example, styrene monomer or vinyl naphthoic acid monomers.

In the formula (VIII), A is an ester-containing or non-ester-containing fluorinated or non-ester selected from C _1-20 alkyl, C _3-20 cycloalkyl, C _6-20 aryl, or C _7-20 aralkyl. It is a fluorinated group. Useful A groups can include fluorinated aromatic moieties, linear fluoroalkyl, or branched fluoroalkyl esters. For example, A is a — [(C (R ^e ) ₂ ) _x (═O) O] _c — (C (R ^f ) ₂ ) _y (CF ₂ ) _z — group, or o-, m-, or p. -Substituted -C ₆ R ^g ₄ -group, wherein each R ^e , R ^f and R ^g are each independently H, F, C _1-6 fluoroalkyl, or C _1-6 alkyl. And c is 0 or 1, x is an integer of 1 to 10, y and z are independently an integer of 0 to 10, and the sum of y + z is at least 1.

Further, in the equation (VIII), Z ^- is a sulfonamide _(-SO 2 _(N-) R 'is an anion of a sulfonate (-SO ₃ ^- is an anionic group containing a) wherein, R' is , C _1-10 alkyl or C _6-20 aryl, or an anion of a sulfonimide When Z ⁻ is a sulfonimide, the sulfonimide has the general structure A—SO ₂ — (N —) — SO ₂ —Y. Can be an asymmetric sulfonimide having ^{2 wherein} A is as described above and Y ² is a linear or branched C _1-10 fluoroalkyl group, eg, Y ² group is trifluoromethanesulfonic acid Alternatively, it can be a C _1-4 perfluoroalkyl group that can be derived from the corresponding perfluoroalkanesulfonic acid such as perfluorobutanesulfonic acid.

  In one embodiment, the monomer of formula (VIII) may have the structure of formula (VIIIa) or (VIIIb)

  In the formula, A and Ra are as defined for formula (VIII).

In formulas (VIII), (VIIIa), and (VIIIb), G ⁺ can have formula (IV)

Wherein X, R ^c and z are the same as described in the above embodiment.

  The polymerization product may further comprise base soluble monomers, lactone containing monomers, or combinations thereof. In one embodiment, the base-soluble monomer can be represented by the above formula (II), and the lactone-containing monomer can be represented by the above formula (III).

  In one embodiment, the copolymer can comprise a polymerization product having any of the following structures:

Where
k, l, m, and q represent the mole fraction of the corresponding repeating unit;
“I” is iodine, and the variable n is the same as above.

  Another embodiment includes a photoresist composition comprising the copolymer and (a) a substrate having one or more layers patterned on the surface thereof; and (b) on the one or more layers patterned. And a layer of the above photoresist composition.

Yet another embodiment is
(A) applying a layer of the photoresist composition to the surface of the substrate;
(B) pattern exposing the photoresist composition layer with activating radiation;
(C) developing the exposed photoresist composition layer to provide a resist relief image; and providing a method of forming an electronic device.

  Hereinafter, the present invention will be described in more detail by way of examples. However, these examples are illustrative and the present disclosure is not limited thereto.

  Table 1 shows the abbreviations and chemical structures of the monomers used in these examples. The synthesis of a monomer designated ECPPDBT F2 is described in US Patent Publication No. 2014 / 0080058A1.

Monomer synthesis The synthesis of two monomers has been described. The Grignard reagent solution used herein was purchased from Aldrich and received. The synthesis scheme for the monomer designated 4-IPBMA is summarized in FIG. Under a nitrogen atmosphere, an oven-dried flask was charged with 100 mL of THF and 100 mL of 0.3 M ethylmagnesium bromide in THF. The Grignard solution was cooled to 0 ° C. and a solution of 4-iodobenzophenone (1,50.0 g, 0.2 mol) in 200 mL THF was added dropwise under a nitrogen atmosphere. The reaction mixture was warmed to room temperature and stirring was continued for 4 hours. To the reaction mixture was added aqueous ammonium chloride solution (100 mL, 1M). The resulting mixture was extracted twice with 100 mL of methylene chloride. The combined organic phases from the extract are concentrated under reduced pressure to give the oily crude product 2- (4-iodophenyl) butan-2-ol (2), which is used in the next step without further purification. Used in. Yield: 61 g.

  In the next step, a solution of methacryloyl chloride (6.20 g, 59.3 mol) in 100 mL of methylene chloride was added to 2- (4-iodophenyl) butan-2-ol (15.0 g, 54.2 mol) and 0 ° C. To the 100 mL methylene chloride solution consisting of triethylamine (6.2 g, 61.3 mol) was added dropwise. After the addition was complete, the mixture was warmed to room temperature and stirred for 16 hours. Thin layer chromatography (TLC) tests showed incomplete conversion. An additional 0.3 equivalents of methacrylyl chloride and 0.3 equivalents of triethylamine were added and the mixture was stirred for an additional 12 hours. The reaction mixture was washed with water (3 × 150 mL) and the organic phase was concentrated. The resulting residue was dissolved in 10 mL of methylene chloride and first passed through a short plug of silica gel using heptane as the eluent and then the fraction containing the product was collected using methylene chloride. To the combined fractions of pure product, 100 mg of dibutylhydroxytoluene (BHT) inhibitor was added and the solvent was completely removed under reduced pressure to produce 10.5 g of monomer 4-IPBMA (3). The product was dried. Yield: 10.5g.

¹ H NMR (CDCl ₃ ), δ: 7.75 (d, 2H, ArH), 7.25 (d, 2H, ArH), 6.20 (s, 1H, CH═CH), 5.70 (s _{, 1H, CH = CH),} 2.01 (s, 3H, CH 3), 1.84-1.54 (m, 5H, CH 3 CH 2), 0.8 (t, 3H, CH 3).

  A synthesis scheme for the monomer designated 3-IPPMA is summarized in FIG.

  To a solution of methyl 3-iodobenzoate (4,30 g, 0.122 mol) in 250 mL of dry THF at 0 ° C. and nitrogen atmosphere was slowly added 100 mL of 0.3 M methylmagnesium bromide in ether. After complete addition of the Grignard reagent, the mixture was slowly warmed to room temperature and stirring was continued for an additional 3 hours. Next, aqueous ammonium chloride (50 mL, 0.5 M) was added to the reaction mixture. The organic solvent was removed by distillation and the product was extracted with 150 mL methylene chloride. The methylene chloride solution was washed twice with 100 mL water. The solvent from the organic phase was completely removed by distillation to give the product 2- (3-iodophenyl) propan-2-ol 5 as a colorless oil that was used in the next step without further purification. . Yield: 32 g (95%).

  In the next step, the reaction flask was charged with 150 mL of 2- (3-iodophenyl) propan-2-ol (5,32 g, 0.115 mol) in methylene chloride. The solution was cooled to 0 ° C. To the reaction flask was added methacryloyl chloride (18.0 g, 0.17 mol) and triethylamine (20 g, 0.20 mol) and the mixture was stirred at room temperature for 16 hours. The organic phase was washed with water (3 × 100 mL) and the solvent was completely removed under reduced pressure. The crude material was dissolved in 150 mL of methylene chloride and washed twice with 100 mL of 0.5 M aqueous sodium carbonate. The organic phase was concentrated and passed through a short pad of basic aluminum oxide using methylene chloride / heptane as the eluent. The solvent fractions containing the product were collected and the solvent was completely removed under reduced pressure to give the product as a colorless oil. Yield: 34 g (90%).

¹ H NMR (CDCl ₃ ), δ: 7.80 (s, 1H, ArH), 7.65 (d, 1H, ArH), 7.46 (d, 1H, ArH), 7.18 (T, 1H) , ArH), 6.12 (S, 1H, CH = CH), 5.65 (s, 1H, CH = CH), 2.10 (s, 3H, CH 3), 1.70 (s, 6H, 2CH _3).

Copolymer synthesis This example illustrates the synthesis of three inventive copolymers and two comparative copolymers. Copolymer 1 was prepared from monomers 4-IPBMA, α-GBLMA, DiHFA at a molar feed ratio of 38.5 / 49.5 / 12. To 45.92 g of propylene glycol monomethyl ether acetate (“PGMEA”), 4-IPBMA (7.97 g, 24.13 mmol), α-GBMMA (5.21 g, 31.0 mmol) and DiHFA (3.32 g, 7. 0 mmol) was dissolved to make a feed solution. 1.68 g of azo initiator dimethyl 2,2′-azobis (2-methylpropionate) (obtained as V-601 from Wako Pure Chemical Industries, Ltd.) in 10.8 g of PGMEA A solution was prepared.

  The polymerization was carried out in a three neck round bottom flask equipped with a water condenser and a thermometer, and the reaction in the flask was monitored. The reactor was charged with 4-IPBMA (0.46 g, 1.40 mmol), α-GBLMA (0.38 g, 2.23 mmol), DiHFA (0.67 g, 1.33 mmol) and 17.52 g of propylene glycol monomethyl ether acetate ( “PGMEA”) was added and the contents were heated to 75 ° C. Feed solution and initiator solution were fed to the reactor using a syringe pump over 4 hours. The contents were then stirred for an additional 2 hours. The contents were cooled to room temperature, diluted to 25 weight percent with tetrahydrofuran (“THF”), and precipitated into a 7: 3 (w / w) mixture of 10 volumes (weight) of heptane and isopropanol. The resulting copolymer 1 was isolated by filtration and vacuum dried at 50 ° C. for 24 hours.

  The polymers listed in Table 2 were prepared using a procedure similar to that used to make Copolymer 1 except that the monomer types and molar feed ratios as specified in Table 2 were used. .

Photoresist Preparation and Processing Photoresist compositions containing Copolymers 1-3 were each independently formulated as summarized in Table 3. The amount of components in Table 3 is based on the total solid content excluding the solvent. The non-polymerizable photoacid generator was ECPPDBT AdOH-TFBS having the following chemical structure.

  The quencher was trioctylamine (TOA). The surfactant was a fluorinated surfactant obtained as POLYFOX ™ PF-656.

  The compositions of two inventive compositions and one comparative photoresist composition are summarized in Table 3. Here, the component amount is expressed as a weight percent based on the total solid content excluding the solvent.

All formulations in Table 3 used propylene glycol monomethyl ether acetate as a solvent. The resist was soft baked at 110 ° C. for 90 seconds and processed on an after-exposure base at 100 ° C. for 60 seconds. By applying a resist on the thick organic antireflective layer, a 248 nanometer contrast curve was generated. The resist was exposed at 248 nanometers with a Canon TELACT tool. After post-exposure baking, the resist was developed for 60 seconds using a 0.26N tetramethylammonium hydroxide solution. Film thickness values were measured using a KLA Tencore OPTPROBE ™ 7341 heat wave tool. The results of this evaluation are shown in Table 4. Here, “248 nm E ₀ ” is an exposure amount of 248 nanometers until clear, and is expressed in millijoules / centimeter ² .

Contrast Curve Measurement Contrast curve measurement using an EUV exposure source (13.5 nm) was performed using a LithoTech Japan EUVES-9000 flood exposure tool. The resist was spin-coated on either the organic lower layer or the silicon wafer, and baked at 110 ° C. for 90 seconds to form a 40-50 nm thick photoresist film. The resist is exposed with a dose of 13.5 nm irradiation with a stepwise increase, post-exposure baking is performed at 100 ° C. for 60 seconds, and development is performed with a 0.26N tetramethylammonium hydroxide aqueous solution for 60 seconds. A relief image pattern of areas and non-exposed areas was formed. Using a KLA Thermowave-7 ellipsometer, the thickness at each exposure area was measured and plotted against exposure. The exposure amount versus the clear value (E ₀ ) was calculated at 10% or less of the remaining film thickness. As can be seen, it contains a terpolymer having 4-IPBMA or 3-IPPMA acid cleavable repeat units as compared to Comparative Photoresist 4 containing terpolymers having “iodo-free” PPMA acid cleavable repeat units. Photoresists 1 and 2 have higher photosensitivity under EUV exposure. Photoresist 3 containing polymer-bound PAG containing 3-IPPMA is more sensitive under EUV exposure compared to Comparative Photoresist 5 containing polymer-bound PAG containing “iodo-free” PPMA acid cleavable repeat units. Have speed.

  While this disclosure has been described in connection with what are presently considered to be practical exemplary embodiments, it is not intended that the invention be limited to the disclosed embodiments, but rather the spirit of the appended claims. It should be understood that various modifications and equivalent arrangements included within the scope and range are intended to be included.

Claims (15)

A monomer having the formula (I),
In formula (I):
R ^a is H, F, —CN, a C _1-10 alkyl group, or a C _1-10 fluoroalkyl group,
R ¹ and R ² are each independently an unsubstituted or substituted C _1-10 linear or branched alkyl group, an unsubstituted or substituted C _3-10 cycloalkyl group, an unsubstituted or substituted C _3-10 alkenylalkyl group. , An unsubstituted or substituted C _3-10 alkynylalkyl group, or an unsubstituted or substituted C _6-30 aryl group, wherein R ¹ and R ² optionally represent at least one linking group selected from O and S R ¹ and R ² together optionally form a ring;
_Represents a monocyclic or polycyclic unsubstituted or substituted C _6-30 arylene group, or a monocyclic or polycyclic unsubstituted or substituted C _3-30 heteroarylene group, “*” and “* ′” Indicate the point of attachment to an adjacent group or atom;
“I” represents iodine;
a monomer wherein n is 1, 2, 3, 4, 5, 6, 7, 8, and 9. The monomer according to claim 1, wherein the C _6-30 arylene group is a monocyclic C _6-30 arylene group, a condensed bicyclic C _6-30 arylene group, or a single-bonded C _6-30 arylene group. The monomer according to claim 1 or 2, wherein each of R ¹ and R ² is an unsubstituted C _1-10 linear or branched alkyl group. One of R ¹ and R ² is an unsubstituted C _1-10 straight chain or branched alkyl group, and the other of R ¹ and R ² is a C _1-10 straight chain substituted with at least one fluorine atom Or the monomer of Claim 3 which is a branched alkyl group.   The monomer according to claim 1, wherein n is 1, 2 or 3.   A copolymer comprising a polymerization product of the monomer according to any one of claims 1 to 5.   The copolymer of claim 6 further comprising a polymerization product of a base soluble monomer, a lactone-containing monomer, or a combination thereof. The base-soluble monomer is represented by the formula (II), the lactone-containing monomer is represented by the formula (III),
Where
Each R ^a is independently H, F, a C _1-10 alkyl group, or a C _1-10 fluoroalkyl group;
Q ¹ is an ester-containing group or a non-ester-containing group selected from C _1-20 alkyl, C _3-20 cycloalkyl, C _6-20 aryl and C _7-20 aralkyl,
W is —C (═O) —OH, —C (CF ₃ ) ₂ OH, —NH—SO ₂ —Y ¹ (where Y ¹ is F or C _1-4 perfluoroalkyl), aromatic A group-OH, or a base-reactive group comprising an adduct of any of the above and a vinyl ether;
a is an integer of 1 to 3,
The copolymer of claim 7, wherein L is a monocyclic, polycyclic, or fused polycyclic C _4-20 lactone-containing group.   The copolymer according to any one of claims 6 to 8, further comprising a polymerization product of a monomer containing a photoacid generator. The photoacid generator monomer containing a polymerizable group is represented by the formula (VIII):
Where
R ^a is independently H, F, a C _1-10 alkyl group, or a C _1-10 fluoroalkyl group,
Q ₂ is a single bond or an ester-containing or non-ester-containing fluorinated or non-fluorinated group selected from C _1-20 alkylene, C _3-20 cycloalkylene, C _6-20 arylene, and C _7-20 aralkylene groups And
A is an ester-containing or non-ester-containing, fluorinated or non-fluorinated group selected from C _1-20 alkylene, C _3-20 cycloalkylene, C _6-20 arylene, and C _7-20 aralkylene,
Z is an anionic moiety comprising a sulfonate, a sulfonamide anion, or a sulfonimide anion;
G ⁺ has the formula (IV)
Where
X is S or I;
Each R ^c is unsubstituted or substituted, halogenated or non-halogenated and is independently C _1-30 alkyl, polycyclic or monocyclic C _3-30 cycloalkyl, polycyclic or monocyclic When C _4-30 aryl and X is S, then one of said R ^c is optionally linked to one adjacent R ^c by a single bond;
10. The copolymer of claim 9, wherein z is 2 or 3, and when X is I, z is 2 or when X is S, z is 3.   A photoresist composition comprising the copolymer of any one of claims 6-10. Further comprising a non-polymerizable photoacid generator monomer having, ^- wherein G ⁺ A
Wherein G ⁺ has the formula (IV)
Where
X is S or I;
Each R ^c is unsubstituted or substituted, halogenated or non-halogenated and is independently C _1-30 alkyl, polycyclic or monocyclic C _3-30 cycloalkyl, polycyclic or monocyclic When C _4-30 aryl and X is S, then one of said R ^c is optionally linked to one adjacent R ^c by a single bond;
z is 2 or 3, z is 2 when X is I, or z is 3 when X is S;
The photoresist composition according to claim 11, wherein A ⁻ is a non-polymerizable organic anion. G ⁺ has the formula (V), (VI), or (VII);
Where
X is I or S;
R ^h , R ⁱ , R ^j , and R ^k are unsubstituted or substituted and are each independently hydroxy, nitrile, halogen, C _1-30 alkyl, C _1-30 fluoroalkyl, C _3-30 cyclo Alkyl, C _1-30 fluorocycloalkyl, C _1-30 alkoxy, C _3-30 alkoxycarbonylalkyl, C _3-30 alkoxycarbonylalkoxy, C _3-30 cycloalkoxy, C _5-30 cycloalkoxycarbonylalkyl, C _{5 -30} cycloalkoxycarbonylalkoxy, _C1-30 fluoroalkoxy, _C3-30 fluoroalkoxycarbonylalkyl, _C3-30 fluoroalkoxycarbonylalkoxy, _C3-30 fluorocycloalkoxy, _C5-30 fluorocycloalkoxycarbonylalkyl , C _5-30 fluorocycloalkoxycarbonylalkoxy, C _6-30 aryl, C _6-30 fluoroaryl, C _6-30 aryloxy, C _6-30 fluoroaryloxy, or —O—C (R ¹¹ R ¹² ) -O- ^{(wherein, R 11} and ^{R 12} are each independently a _{C 2-30} acetal group containing a hydrogen) or _{C 1-30} alkyl group, or each of which is unsubstituted, or Replaced by
Ar ¹ and Ar ² are independently a C _10-30 condensed or single-bonded polycyclic aryl group,
R ¹ is a lone pair when X is I, or a C _6-20 aryl group when X is S, p is an integer of 2 or 3, and X is I P is 2, and when X is S, p is 3,
q and r are each independently an integer of 0 to 5;
The photoresist composition according to claim 12, wherein s and t are each independently an integer of 0 to 4.   14. A coated substrate comprising: (a) a substrate having one or more layers patterned on its surface; and (b) any of the patterned one or more layers. A coated substrate comprising: a layer of the photoresist composition according to claim 1. A method of forming an electronic device comprising:
(A) On the surface of a board | substrate, apply | coating the layer of the photoresist composition of any one of Claims 11-13,
(B) pattern exposing the photoresist composition layer with activating radiation;
(C) developing the exposed photoresist composition layer to provide a resist relief image.